SWF

Introduction

• Simple Workflow Service (SWF) is a fully-managed state tracker and task coordinator

• Code run on EC2 (not serverless)

• If the app's steps take more than 500 milliseconds to complete, SWF can help

• Step Functions is recommended, unless:

  • Need external signals to intervene in the processes

  • Need child processes that return values to parent processes

  • AWS Mechanical Turk

Feature

• Has a retention period of 14 days, can set up to 1 year

• Provide task-oriented API

• Ensure a task is run only once

• Keep track of tasks

• Cpncept of steps:

  • Decision step

  • Activity step

  • Human intervention step

• SWF actors (Not support Spot Instance):

  • Starter: like a trigger

  • Decider: control the flow logic (if..., then..., else...)

  • Worker: carry out the activity